1. Technical Field
The present invention relates to a light source device, a projector, and a method of manufacturing a light source device.
2. Related Art
A light emitting element such as a light emitting diode or a semiconductor laser used for a light source device is damaged in some cases when emitting light if an organic substance or moisture adheres to the light emitting element. Therefore, the light source device is provided with a structure of shielding the light emitting element from the outside air. In the past, as such a structure, there has been known an airtight sealing structure of bonding a substrate made of ceramics and a cover made of glass to each other to seal the light emitting element (e.g., JP-A-2007-123444 (Document 1)). In recent years, due to downsizing of the light source device, there has been studied the light source device having a structure of mounting a plurality of light emitting elements on a substrate in high density.
In general, since these light emitting elements generate heat when emitting light, there is a possibility that the light emitting elements deteriorate or the light emitting characteristics degrade due to the heat. Therefore, the light source device is configured so as to prevent the light emitting elements from becoming high in temperature by discharging the heat generated by the light emitting elements to the outside.
However, in the light source device described in Document 1, there is used the substrate made of ceramics. Although the heat generated by the light emitting element is discharged to the outside via the substrate, the substrate made of ceramics is low in thermal conductivity (heat radiation performance), and is easy to accumulate heat. Therefore, in the light source device described in Document 1, in order to prevent the light emitting elements from becoming high in temperature, it is necessary to decrease the amount of heat generation per unit area of the substrate. In order to achieve the above, it is effective to decrease the number of light emitting elements per unit area. However, in this case, since it is necessary to increase the size of the substrate for achieving the necessary light intensity, downsizing of the whole of the light source device has been difficult.
In the case of bonding the substrate and the cover to each other using a bonding member made of an inorganic substance such as low-melting point glass, it is necessary to heat the whole of the light source device to a temperature equal to or higher than the melting point of the bonding member. Therefore, in some cases, the light emitting elements deteriorate due to the heating, and the desired light emitting characteristics cannot be obtained.